The present invention relates to orthodontia. More particularly, the present invention relates to the selection of orthodontic appliances, e.g., orthodontic bands.
Orthodontic treatment involves movement of the teeth to desired positions. During treatment, small slotted bodies (known as brackets) are typically bonded to anterior teeth, and an arch wire held in the slots functions as a track to guide movement of the teeth. Teeth are commonly moved by bends or twists placed in the arch wire, or by elastic members connected between the brackets of certain teeth.
Ends of the arch wires are normally anchored in devices known as buccal tubes that are mounted on molar teeth. Occasionally, buccal tubes are bonded directly to an exterior surface of the molar teeth using a small amount of adhesive in a manner similar to the method of bonding brackets directly to anterior teeth. However, buccal tubes are often subjected to relatively large forces from occluding teeth, as well as forces exerted by the arch wire. As a result, the buccal tubes may spontaneously debond from the tooth. Rebonding of the buccal tube can be achieved, but is a nuisance both to the orthodontist and the patient.
As a consequence, buccal tubes are commonly welded to metallic orthodontic bands that are placed around the molar teeth to provide a stable base for mounting the buccal tubes. Orthodontic bands are made in a variety of shapes and sizes so that a band with the proper contour and circumferential dimensions can be selected in each instance to tightly fit onto the molar tooth. Bands are also available for use with anterior, cuspid, and bicuspid teeth in instances where a relatively strong connection to such teeth is desired.
Band selection is often made by the orthodontist by first visually estimating the size of the chosen tooth and then selecting a few bands of different sizes that appear to be close in size to the tooth. Generally, the method of fitting such bands is for the orthodontist to place a band over the tooth and xe2x80x9cfeelxe2x80x9d how it fits. Different size bands are trial fitted until an acceptable fit, or best-fit, is found.
During the fitting procedure, the bands selected by the orthodontist are placed on a set-up tray that is located by the patient. Once the best-fit band is found, the remaining bands are sterilized to reduce the risk of cross-contamination before being returned to a storage container, i.e., reinventoried.
Typically, orthodontic bands need to fit around the tooth geometry in a fairly precise manner to allow for good performance. After the proper orthodontic band is selected, the band is subjected to a burnishing process wherein a rotating tool is used to form the band to fit the contours of the tooth. Orthodontic bands have a fundamental geometry that stays constant throughout the size range. Generally, the different sizes of the orthodontic bands are made by scaling a fundamental geometry up or down.
The manual method of fitting an orthodontic band to the tooth, as described above, is a very time consuming process. Further, this manual process requires that trial bands be sterilized and reinventoried after the best fit band is found.
The present invention is directed toward orthodontic appliance selection that is performed in an automatic manner instead of a manual fitting process as described in the Background of the Invention section. In one embodiment of the invention, a computer implemented method compares tooth geometry to known band geometry such that a properly sized band can be selected without manual fitting techniques.
A computer implemented method of orthodontic appliance selection according to the present invention includes providing data representative of one or more teeth of a patient and providing data representative of a set of orthodontic appliances. Each orthodontic appliance of the set of orthodontic appliances has an appliance parameter that varies from the other orthodontic appliances of the set. At least one geometrical parameter of the one or more teeth of the patient is determined using the data representative thereof. The at least one geometrical parameter is compared to the data representative of the set of orthodontic appliances and one orthodontic appliance of the set of orthodontic appliances is selected based on the comparison.
In one embodiment of the method, the set of orthodontic appliances includes a set of orthodontic bands with each band of the set having a different size. Such bands may be precoated with an adhesive material.
In one embodiment of the band selection method, the determination of the geometrical parameter of the one or more teeth of the patient includes determining a geometrical parameter associated with a portion of a tooth of the patient that lies orthogonal to a center axis of the tooth, e.g., a perimeter length of a cross-section of the tooth of the patient, an area of a cross-section of the tooth, a volume of a section of the tooth, a width of a cross-section of the tooth, etc. In other embodiments of the method, the center axis may be determined based on a best fit cylinder for data representative of the tooth or based on a best fit occlusal plane for the data representative of the tooth.
A method for use in orthodontia is also described. The method includes generating data representative of at least one geometrical parameter of a tooth of a patient and providing data representative of a set of orthodontic bands. Each orthodontic band of the set has an associated band parameter different from the other orthodontic bands of the set. The at least one geometrical parameter is compared to the data representative of the set of orthodontic bands and one of the set of orthodontic bands is selected based on the comparison. The selected band is applied to the tooth. In different embodiments of the method, the set of orthodontic bands may or may not be precoated with an adhesive material.
A computer readable medium tangibly embodying a program executable for use in selection of orthodontic appliances includes a program portion for recognizing data representative of one or more teeth of a patient and for recognizing data representative of a set of orthodontic appliances. Each orthodontic appliance of the set of orthodontic appliances has an appliance parameter that varies from the other orthodontic appliances of the set. The program further determines at least one geometrical parameter of the one or more teeth of the patient using the data representative thereof. Further, a comparison of the at least one geometrical parameter is made to the data representative of the set of orthodontic appliances and one orthodontic appliance of the set of orthodontic appliances is selected based on the comparison.
A system for use in orthodontia according to the present invention includes memory storing data representative of at least one geometrical parameter of a tooth of a patient and memory storing data representative of a set of orthodontic bands. Each orthodontic band of the set has an associated band parameter different from the other orthodontic bands of the set. The system further compares the at least one geometrical parameter to the data representative of the set of orthodontic bands and selects one of the set of orthodontic bands based on the comparison.
A method of fitting an orthodontic band to a tooth of a patient according to the present invention is also described. The method includes providing a set of orthodontic bands with at least a portion of each orthodontic band coated with an adhesive material. The method further includes selecting one orthodontic band of the set of orthodontic bands based on a geometrical parameter of the tooth of the patient. Thereafter, the selected band is applied to the tooth of the patient.
An article according to the present invention includes a container and a set of orthodontic bands received in the container. Each of the set of orthodontic bands has substantially a same fundamental geometrical configuration and each of the orthodontic bands is of a different size relative to the other orthodontic bands. Further, each orthodontic band has a precoat adhesive material applied to at least a portion thereof.